Xen 4.4.x/4.5.x/4.6.x/4.7.x QEMU Shared Ring Processor Host race condition

CVSS Meta Temp Score
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CTI Interest Score
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7.3$0-$5k0.00

Summaryinfo

A vulnerability categorized as problematic has been discovered in Xen 4.4.x/4.5.x/4.6.x/4.7.x. Affected by this vulnerability is an unknown functionality of the component QEMU Shared Ring Processor. Executing a manipulation can lead to race condition (Host). This vulnerability appears as CVE-2016-9381. The attack requires local access. There is no available exploit. Applying a patch is advised to resolve this issue.

Detailsinfo

A vulnerability classified as critical was found in Xen 4.4.x/4.5.x/4.6.x/4.7.x (Virtualization Software). This vulnerability affects an unknown functionality of the component QEMU Shared Ring Processor. The manipulation with an unknown input leads to a race condition vulnerability (Host). The CWE definition for the vulnerability is CWE-362. The product contains a code sequence that can run concurrently with other code, and the code sequence requires temporary, exclusive access to a shared resource, but a timing window exists in which the shared resource can be modified by another code sequence that is operating concurrently. As an impact it is known to affect confidentiality, integrity, and availability. CVE summarizes:

Race condition in QEMU in Xen allows local x86 HVM guest OS administrators to gain privileges by changing certain data on shared rings, aka a "double fetch" vulnerability.

The bug was discovered 11/22/2016. The weakness was presented 11/22/2016 by yanghongke with Huawei as XSA-197 as confirmed security advisory (Website). The advisory is shared for download at xenbits.xen.org. The public release was coordinated in cooperation with the vendor. This vulnerability was named CVE-2016-9381 since 11/17/2016. The attack needs to be approached locally. The successful exploitation needs a single authentication. There are neither technical details nor an exploit publicly available.

The vulnerability scanner Nessus provides a plugin with the ID 900047 , which helps to determine the existence of the flaw in a target environment. The commercial vulnerability scanner Qualys is able to test this issue with plugin 276244 (Fedora Security Update for xen (FEDORA-2016-999e1a6927)).

Applying a patch is able to eliminate this problem. A possible mitigation has been published immediately after the disclosure of the vulnerability.

The vulnerability is also documented in the databases at Tenable (900047), SecurityFocus (BID 94476†) and SecurityTracker (ID 1037344†). See VDB-92454, VDB-92455, VDB-92462 and VDB-93307 for similar entries. VulDB is the best source for vulnerability data and more expert information about this specific topic.

Productinfo

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Version

License

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 7.5
VulDB Meta Temp Score: 7.3

VulDB Base Score: 7.5
VulDB Temp Score: 7.2
VulDB Vector: 🔍
VulDB Reliability: 🔍

NVD Base Score: 7.5
NVD Vector: 🔍

CVSSv2info

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VulDB Base Score: 🔍
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Exploitinginfo

Name: Host
Class: Race condition / Host
CWE: CWE-362
CAPEC: 🔍
ATT&CK: 🔍

Physical: Partially
Local: Yes
Remote: No

Availability: 🔍
Status: Not defined

EPSS Score: 🔍
EPSS Percentile: 🔍

Price Prediction: 🔍
Current Price Estimation: 🔍

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Nessus ID: 900047
Nessus File: 🔍

OpenVAS ID: 58605
OpenVAS Name: Fedora Update for xen FEDORA-2016-999e1a6927
OpenVAS File: 🔍
OpenVAS Family: 🔍

Qualys ID: 🔍
Qualys Name: 🔍

Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Patch
Status: 🔍

Reaction Time: 🔍
0-Day Time: 🔍
Exposure Time: 🔍

Timelineinfo

11/17/2016 🔍
11/22/2016 +5 days 🔍
11/22/2016 +0 days 🔍
11/22/2016 +0 days 🔍
11/22/2016 +0 days 🔍
11/25/2016 +3 days 🔍
11/25/2016 +0 days 🔍
01/23/2017 +59 days 🔍
05/14/2026 +3398 days 🔍

Sourcesinfo

Advisory: XSA-197
Researcher: yanghongke
Organization: Huawei
Status: Confirmed
Confirmation: 🔍
Coordinated: 🔍

CVE: CVE-2016-9381 (🔍)
GCVE (CVE): GCVE-0-2016-9381
GCVE (VulDB): GCVE-100-93808

OVAL: 🔍

SecurityFocus: 94476 - Xen CVE-2016-9381 Privilege Escalation Vulnerability
SecurityTracker: 1037344

See also: 🔍

Entryinfo

Created: 11/25/2016 11:52
Updated: 05/14/2026 16:49
Changes: 11/25/2016 11:52 (70), 06/10/2019 06:42 (14), 05/14/2026 16:49 (18)
Complete: 🔍
Cache ID: 216::103

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